The interface class defines a group of sequence classes that do not keep their sequence information in memory but store it in a file. This makes it possible to work with very large files even with limited RAM.

The most important consequence of file caching for sequences is that you do not want to inspect the sequence unless absolutely necessary. These sequences typically override the length() method not to check the sequence.

The seq() method is not resetable, if you want to add to the end of the sequence you have to use add_sequence_as_string(), for any other sequence changes you'll have to create a new object.

rather than to the module maintainer directly. Many experienced and reponsive experts will be able look at the problem and quickly address it. Please include a thorough description of the problem with code and data examples if at all possible.

Title : add_sequence_as_string
Usage : $seq->add_sequence_as_string("CATGAT");
Function: Appends additional residues to an existing object.
This allows one to build up a large sequence without
storing entire object in memory.
Returns : Current length of sequence
Args : string to append